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| High Island | Sharp Island | Ung Kong Group | Wang Chau | Basalt Island | Ninepin Group |
| Ma Shi Chau | Lai Chi Chong | Yan Chau Tong | Bluff Head | Tung Ping Chau |
| Port Island | Kat O | Ap Chau | Lai Chi Wo |


Magnificent sea stacks of Ung Kong Group–Bluff Island (Sha Tong Hau Shan)

Ug Kong Group has no tourist facilities (such as public pier or trail) available. To prevent accidents, please observe from a boat and avoid getting ashore.

The Ung Kong Group is located south of High Island, and includes Wang Chau, Basalt Island, Bluff Island and Kam Chung Ngam of Jin Island (Tiu Chung Chau). The coasts of Wang Chau, Basalt Island and Bluff Island are studed with densely arranged hexagonal volcanic rock columns. Under the extended impact of wind and waves on these volcanic rock columns on the coast of the Ung Kong Group has resulted in magnificent coastal landforms, such as steep cliffs, sea arches, sea stacks and sea caves. The most famous landforms are the 45m-high Lam Wan Kok Arch on Basalt ISland, 50m-high Wang Chau Kok Arh on Wang Chau, 25m-high Sha Tong Hau Cave on Bluff Island, and the Tiu Chung Arch on the Jin Island, which are the top four sea arches in Hong Kong. As the Ung Kong Group is within the core protection area, and in view of the strong wind, big waves and dangerous terrain, sightseeing is suitable only on calm summer days, and only boat tours with no land excursion.


Background Information

Background Information


Bluff Island (Sha Tong Hau Shan), or Ung Kong Chau, lies west of Basalt Island and south of Town Island (Fo Tau Fan Chau). In the southern corner of this small island you can find one of the four biggest sea caves in our eastern waters, the Sha Tong Hau Cave.

Viewed from above, Bluff Island resembles a turtle with four legs stretched out wide. Lushly wooded slopes of the rounded hills roll gently down to scenic sandy bays. This is an ideal place to study rhyolite. Formations in clearly defined layers are prominent across the island, and along the wavy shores, huge blocks tower by the water. Fan Tap Pai in the south is one of the most breathtaking coastal rock scenes in Hong Kong. This huge sea cave cuts right through the island and it is just wide enough for a boat to sail past. Not a bad idea for a leisure sea expedition. Bluff Island is also a diving hot spot. An increasing number of divers are coming here to explore the mysterious ocean.


Geological Information

Most parts of the exposed stratum of Bluff Island belong to the Early Cretaceous Kau Sai Chau Volcanic Group.

From the Late Jurassic to the Early Cretaceous, this region was the site of earth shaking changes. It began about 146 million years ago (Late Jurassic) when there were violent magma activities. Fiery underground magma intruded upwards, melting ancient rocks along its path. It forced its way through cracks and thrust along crustal faults or weak bands until it reached the surface to cause great volcanic eruptions. Sometimes magma was pressed inside underground voids. It created such an immense force that when it finally broke out it made catastrophic impact. Explosion shot volcanic ash and gravels high into the air. Lava was vented out from the crater from where it coursed down the slopes, igniting fires and generating great clouds of ash and fume.

According to data for determining the absolute age of rocks, volcanic eruptions and magma intrusion activities took a cyclical pulse pattern. In every cycle, major eruptions were always followed by great magma intrusions. Such cyclical volcanic magma activities can be categorised into four stages, and consequently there are four volcanic rock groups in Hong Kong ranging from old to new : Tsuen Wan Group, Lantau Group, Repulse Bay Group and Kau Sai Chau Group. Judging by the exposed stratum of Bluff Island, we know that eruptions took place in the 4th stage.

Geological Information   Geological Information

Geological Information
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How to get there

Private boat hire is required or join a local tour. As there are  many outlying islands in Sai Kung, it is a good idea to hire a boat at Sai Kung pier and sail around Jin Island (Tiu Chung Chau), Bluff Island, Basalt Island, Wang Chau and other islets. You can have a close look at the rugged primitive rock formations and spectacular rock cliffs that plunge deep into the sea.

(Note: Only suitable for days when the weather is calm and stable. To prevent accidents, please observe from a boat and avoid getting ashore.)






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